The Agouti-Related Protein (AgRP) plays a central role in energy balance by reducing signaling through the hypothalamic melanocortin receptors (MCRs) 3 and 4, in turn stimulating feeding and decreasing energy expenditure. The inventors have examined the functions of the N-terminal extension and a C-terminal loop of AgRP in controlling appetite. The present study suggests new strategies for the development of potent orexigenic species, and treating wasting conditions such as cachexia.